Trim the End of these Beziers

jmorri36

Hi, I have this sketch that I wrote to generate a sort of wobbly circle. I'm using beziers to draw a continuous curve through the points. Only thing is, I would like to trim the ends of the beziers so that I'm only left with the middle section. Is this possible, or is there a better way of drawing that curve through control points?

jmorri36

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jmorri36

float step = .01;    // resolution of lines
float r = 300;     // radius

int opacity = 0;

float a = 1;
float b = 1;

float x1;
float y1;
float x2;
float y2;
float theta1;
float rR;
float[] bez = {0, 0, 0, 0};

int count;

float xa;
float xb;
float xc;
float xd;
float xe;
float xf;
float xg;
float xh;
float xi;
float xj;
float xk;
float xl;
float xm;
float xn;
float xo;
float xp;
float xq;

float ya;
float yb;
float yc;
float yd;
float ye;
float yf;
float yg;
float yh;
float yi;
float yj;
float yk;
float yl;
float ym;
float yn;
float yo;
float yp;
float yq;

void setup() {
  //size(1080, 720);
  fullScreen();
  background(0);
  stroke(255);
  noFill();
  strokeWeight(1);
  smooth();
  frameRate(5);
}



void draw() {

  background(0);

  // the center point of the circle
  float h = width/2;    
  float k = height/2;

  //step = random(.01,.5);
  step = .45;

  rR = 1;

  for (float theta = 0; theta <= 2*PI; theta += step) {

    float R = random(-30, 30);
    //rR = rR + R;
    //r = r + R;

    //bez[0] = x2;
    //bez[1] = y2;

    x1 = h + (r+R)*cos(theta);
    y1 = k + (r+R)*sin(theta);
    //line(x1, y1, x2, y2);
    //ellipse(x, y, s, s);
    //ellipse(x1, y1, s, s);
    theta1 = theta;
    theta1 = theta1 - step;

    x2 = x1;
    y2 = y1;
    saveCoordinates();
  }
  count = 0;

  drawBezier();
  //drawCurve();

  text(int(frameRate) + " fps", 30, 30, 30);
}



void saveCoordinates() {

  count += 1;
  switch(count) {
  case 1: 
    xa = x1;
    ya = y1;
    break;
  case 2: 
    xb = x1;
    yb = y1;
    break;
  case 3: 
    xc = x1;
    yc = y1;
    break;
  case 4: 
    xd = x1;
    yd = y1;
    break;
  case 5: 
    xe = x1;
    ye = y1;
    break;
  case 6: 
    xf = x1;
    yf = y1;
    break;
  case 7: 
    xg = x1;
    yg = y1;
    break;
  case 8: 
    xh = x1;
    yh = y1;
    break;
  case 9: 
    xi = x1;
    yi = y1;
    break;
  case 10:
    xj = x1;
    yj = y1;
    break;
  case 11:
    xk = x1;
    yk = y1;
    break;
  case 12:
    xl = x1;
    yl = y1;
    break;
  case 13:
    xm = x1;
    ym = y1;
    break;
  case 14:
    xn = x1;
    yn = y1;
    break;
  case 15:
    xo = x1;
    yo = y1;
    println("here2");
    break;
  case 16:
    xp = x1;
    yp = y1;
    println("here1");
    break;
  case 17:
    xq = x1;
    yq = y1;
    println("here");
    break;
  default:
    println("excess case");
    break;
  }
}

void drawBezier() {

  bezier(xa, ya, xb, yb, xc, yc, xd, yd);
  bezier(xb, yb, xc, yc, xd, yd, xe, ye);
  bezier(xc, yc, xd, yd, xe, ye, xf, yf);
  bezier(xd, yd, xe, ye, xf, yf, xg, yg);
  bezier(xe, ye, xf, yf, xg, yg, xh, yh);
  bezier(xf, yf, xg, yg, xh, yh, xi, yi);
  bezier(xg, yg, xh, yh, xi, yi, xj, yj);
  bezier(xh, yh, xi, yi, xj, yj, xk, yk);
  bezier(xi, yi, xj, yj, xk, yk, xl, yl);
  bezier(xj, yj, xk, yk, xl, yl, xm, ym);
  bezier(xk, yk, xl, yl, xm, ym, xn, yn);
  bezier(xl, yl, xm, ym, xn, yn, xa, ya);
  bezier(xm, ym, xn, yn, xa, ya, xb, yb);
  bezier(xn, yn, xa, ya, xb, yb, xc, yc);
}

void drawCurve() {

  curve(xa, ya, xb, yb, xc, yc, xd, yd);
  curve(xb, yb, xc, yc, xd, yd, xe, ye);
  curve(xc, yc, xd, yd, xe, ye, xf, yf);
  curve(xd, yd, xe, ye, xf, yf, xg, yg);
  curve(xe, ye, xf, yf, xg, yg, xh, yh);
  curve(xf, yf, xg, yg, xh, yh, xi, yi);
  curve(xg, yg, xh, yh, xi, yi, xj, yj);
  curve(xh, yh, xi, yi, xj, yj, xk, yk);
  curve(xi, yi, xj, yj, xk, yk, xl, yl);
  curve(xj, yj, xk, yk, xl, yl, xm, ym);
  curve(xk, yk, xl, yl, xm, ym, xn, yn);
  curve(xl, yl, xm, ym, xn, yn, xa, ya);
  curve(xm, ym, xn, yn, xa, ya, xb, yb);
  curve(xn, yn, xa, ya, xb, yb, xc, yc);
}